Greek and Turkish Cypriot leaders trying to unite Cyprus staked out opening positions that were far apart on Thursday at the start of talks marred by a bomb outside the home of the Turkish Cypriot prime minister.
The percussion grenade or "sound bomb" outside pro-reunification Prime Minister Mehmet Ali Talat's home just hours before he took part in the talks shattered windows and damaged his front door but nobody was hurt.
UN officials said the early morning blast had no effect on two hours of discussions that aim to unite the Greek and Turkish communities before the island joins the European Union on May 1.
"It was a very constructive session with ample goodwill and a business like spirit from the two sides," said UN envoy Alvaro de Soto.
But in comments to reporters, Greek Cypriot President Tassos Papadopoulos and Turkish Cypriot leader Rauf Denktash indicated how tough negotiations would be as they try to meet deadlines starting on March 22 and leading up to April 21 referendums.
Papadopoulos said that most issues raised for negotiation by the Turkish Cypriots conflicted with the UN plan.
Denktash said he was already concerned about what impact reunification with the far wealthier Greek Cypriots would have on his northern enclave's economy.
"The transition periods must include measures to protect our economy from destruction from the stronger economy of the south (Greek Cypriots)," Denktash said.
Denktash said other concerns included how Turkish Cypriot and EU law would mesh and how many of Turkey's 35,000 troops on the island would stay not just if a united Cyprus joined the EU but even if Turkey itself was admitted in the future.
"We want Turkish forces in Cyprus even after Turkey joins the EU, for psychological reasons," Denktash said.
De Soto said the two leaders, who met at an abandoned airport compound used by UN peacekeepers for what has been billed as the best chance to end three decades of bitter division, would gather again on Friday.
He said they would meet daily for the foreseeable future.
The UN timetable calls for the Greek and Turkish Cypriot leaders to negotiate until March 22, when Greece and Turkey are likely to join in until March 29. The final plan would go to referendums in both parts of Cyprus on April 21.
Failure to reach a deal will mean only the Greek Cypriot south joins the EU, and Turkey knows its efforts to start its own membership talks could hinge on the Cyprus peace process.
The UN plan involves turning Cyprus into a loose power-sharing federation as well as territory trade-offs, return of refugees and a gradual scaling down of Greek and Turkish forces on the heavily militarised Mediterranean island.